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At least 55 records · Page 3Linked to original sources
USGS2011

Introduction to fire danger rating and remote sensing - Will remote sensing enhance wildland fire danger prediction?

While ‘Fire Danger’ per se cannot be measured, the physical properties of the biotic and abiotic world that relate to fire occurrence and fire behavior can. Today, increasingly sophisticated Remote Sensing methods are being developed to more accurately detect fuel properties such as species composition (fuel types), vegetation structure or plant water content - to name a few. Based on meteorological input data and physical, semi-physical or empirical model calculations, Wildland Fire Danger Rating Systems provide ‘indirect values’ - numerical indices - at different temporal scales (e.g., daily, weekly, monthly) denoting the physical conditions that may lead to fire ignition and support fire propagation. The results can be expressed as fire danger levels, ranging from ‘low’ to ‘very high’, and are commonly used in operational wildland fire management (e.g., the Canadian Fire Weather Index [FWI] System, the Russian Nesterov Index, or the U.S. National Fire Danger Rating System [NFDRS]). Today, fire danger levels are often turned into broad scale maps with the help of Geographical Information Systems (GIS) showing the areas with the different fire danger levels, and are distributed via the World Wide Web. In this chapter we will outline some key issues dealing with Remote Sensing and GIS techniques that are covered in the following chapters, and elaborate how the Fire Danger Rating concepts could be integrated into a framework that enables comprehensive and sustainable wildland fire risk assessment. To do so, we will first raise some general thoughts about wildland fires and suggest how to approach this extremely complex phenomenon. Second, we will outline a possible fire risk analysis framework and third we will give a short overview on existing Fire Danger Rating Systems and the principles behind them.

Series in Remote Sensing↗
USGS2016

Biogeography of boreal passerine range dynamics in western North America: past, present, and future

Many of the Neotropical migrant bird species that breed throughout the Canadian boreal region are not found in the Alaskan boreal region, separated by the northwestern cordilleran mountains, despite the presence of climatically suitable habitat. We asked whether biological or climatic factors constrain certain species from crossing this geographic barrier. Analyzing a comprehensive dataset for 80 boreal passerine species, we used phylogenetic logistic regression to evaluate the relative importance of physical, migratory and competition metrics versus current and paleoclimatic suitability factors. Controlling for current climatic suitability within boreal Alaska, we found that species with the greatest climatic suitability across the northwestern cordillera, presently and also during the mid-Holocene period, were most likely to be regular breeders in the Alaskan boreal region. Migratory strategy also played a role, but could not be disentangled from its strong phylogenetic basis. Our analysis suggests that the perceived barrier of the northwestern cordillera may be easily weakened as climate change improves conditions there for many forest species. The weakening of this barrier may lead to relatively rapid range expansions and the reshuffling of species communities. Species’ realized distributional shifts will be a function of the interplay between a changing climate and static topographic features.

Ecography: Pattern and Diversity in Ecology↗
USGS2007

A GIS library of multibeam data for Massachusetts Bay and the Stellwagen Bank National Marine Sanctuary, offshore of Boston, Massachusetts

Introduction The U.S. Geological Survey (USGS) has mapped the sea floor of the Stellwagen Bank National Marine Sanctuary and western Massachusetts Bay, offshore of Boston, Massachusetts (figure 1a, figure 1b). The mapping was carried out using a Simrad Subsea EM1000 Multibeam Echo Sounder (95 kHz) on the Frederick G. Creed on four cruises between 1994 and 1998. The mapping was conducted in cooperation with the National Oceanic and Atmospheric Administration (NOAA) and with support from the Canadian Hydrographic Service and the University of New Brunswick. This GIS Library contains images and grids of bathymetry, shaded relief bathymetry, and backscatter intensity data from these surveys in an Environmental Systems Research Institute (http://www.esri.com) (ESRI) ArcMap 9.1 Geographic Information System (GIS) project. The shapefiles, images, grids and associated metadata may also be downloaded individually. Descriptions and interpretations of the data are available in a series of published maps.

Data Series↗
USGS2024

Case definitions for wildlife diseases

Welcome to the first manual of “Case Definitions for Wildlife Diseases,” a “living” electronic publication. The plan is to add and update this manual’s case definitions periodically as warranted; thus, this manual will never be completed, and readers should download the latest versions of specific chapters (that is, definitions) when available. Constructive suggestions from readers are welcome and will help guide adjustments as this project progresses. The purpose of this manual is to provide case definitions for selected diseases of importance to wildlife in Canada and the United States. Case definitions provide standard sets of criteria for classifying the degree of certainty of a particular diagnosis and help improve surveillance data quality and comparability. Better data and standardization allow for improved data sharing, which increases geographic and species surveillance coverage and permits more robust analyses. The definitions included in this manual have been developed by veterinary pathologists, epidemiologists, and wildlife biologists primarily from the U.S. Geological Survey National Wildlife Health Center (NWHC) and Canadian Wildlife Health Cooperative (CWHC). Pathologists from each organization reviewed and finalized the definitions. Each case definition has been peer reviewed by two scientific experts before publication. This manual begins with the case definition template. This generic template includes four sections: “Individual, Place, and Time Criteria for Diagnosis and Testing,” “Field Criteria for Diagnosis,” “Laboratory Criteria for Diagnosis,” and “Epidemiological Linkage Criteria for Diagnosis” and can be used to guide development of new case definitions. Information in each section is then combined to provide an overall case classification. Disease diagnoses are classified as “Confirmed,” “Presumptive,” or “Suspected;” and evidence of a pathogen or toxin is classified as “Exposed” or “Present/Detected.” Each subsequent chapter is then a case definition for a specific disease of wildlife, and infectious and non-infectious diseases are included.

Techniques and Methods↗
USGS2015

Dam-breach analysis and flood-inundation mapping for selected dams in Oklahoma City, Oklahoma, and near Atoka, Oklahoma

Dams provide beneficial functions such as flood control, recreation, and storage of water supplies, but they also entail risk; dam breaches and resultant floods can cause substantial property damage and loss of life. The State of Oklahoma requires each owner of a high-hazard dam, which the Federal Emergency Management Agency defines as dams for which failure or improper operation probably will cause loss of human life, to develop an emergency action plan specific to that dam. Components of an emergency action plan are to simulate a flood resulting from a possible dam breach and map the resulting downstream flood-inundation areas. The resulting flood-inundation maps can provide valuable information to city officials, emergency managers, and local residents for planning an emergency response if a dam breach occurs. This report presents results of a cooperative study by the U.S. Geological Survey and the City of Oklahoma City to model dam-breach scenarios at 11 dams controlled and operated by Oklahoma City, Okla., and to map the potential flood-inundation areas of such dam breaches. To assist the City of Oklahoma City with completion of the emergency action plans for the 11 dams, the U.S. Geological Survey used light detection and ranging (lidar) elevation data (2004), which produced a 2-foot contour elevation map for the flood plains around Oklahoma City. A 5-meter Digital Terrain Map was used to model the flood plain below Atoka Reservoir in southeastern Oklahoma. Digital-elevation models, field survey measurements, hydraulic data, and hydrologic data (U.S. Geological Survey streamflow-gaging stations North Canadian River below Lake Overholser near Oklahoma City, Okla. [07241000], and North Canadian River at Britton Road at Oklahoma City, Okla. [07241520]), were used as inputs for the one-dimensional dynamic (unsteady-flow) models using Hydrologic Engineering Centers River Analysis System (HEC–RAS) software. The modeled flood elevations were exported to a geographic information system to produce flood-inundation maps. Water-surface profiles were developed for a 75-percent probable maximum flood dam-breach scenario and a sunny-day dam-breach scenario, as well as for maximum flood-inundation elevations and flood-wave arrival times at selected bridge crossings. Points of interest such as community-services offices, recreational areas, water-treatment plants, and wastewater-treatment plants were identified on the flood-inundation maps.

Oklahoma↗
USGS2000

Mitochondrial DNA diversity North American and European Atlantic salmon with emphasis on the downeast rivers of Maine

The displacement loop and NADH-1 dehydrogenase regions of mitochondrial DNA (mtDNA) were amplified by the polymerase chain reaction in 954 Atlantic salmon and digested with 40 restriction endonucleases. Variation was detected with 10 enzymes, resulting in 21 composite haplotypes which were strongly patterned geographically with a major discontinuity observed between most North American (NA) and European salmon. Significant heterogeneity of haplotype frequencies was found within and among all classification levels (continent, country, and river). Haplotype frequencies were significantly different across continents, within European samples, within NA samples, within Canadian samples, within wild Maine samples, within captive Maine strains, and between captive and wild Maine strains. Nine haplotypes occurred only in NA, seven in Maine, three only in Maine, and 11 occurred only in Europe. Some Maine rivers had only a single haplotype, suggesting that effective population sizes may be low. The second most frequent European haplotype occurred in tributaries to one Newfoundland river. Gene trees based on parsimony and genetic distance suggest that the haplotypes are monophyletic within each continent, and that the haplotype found on both continents is intermediate between those of Europe and NA, suggesting common ancestry of all haplotypes.

Maine↗
USGS2018

Comparison of genetic and visual identification of cisco and lake whitefish larvae from Chaumont Bay, Lake Ontario

Cisco Coregonus artedi are an important component of native food webs in the Great Lakes, and their restoration is instrumental to the recovery of lake trout Salvelinus namaycush and Atlantic salmon Salmo salar . Difficulties with visual identification of larvae can confound early life history surveys, as cisco are often difficult to distinguish from lake whitefish C. clupeaformis . We compared traditional visual species identification methods to genetic identifications based on barcoding of the mitochondrial cytochrome C oxidase I gene for 726 coregonine larvae caught in Chaumont Bay, Lake Ontario. We found little agreement between the visual characteristics of cisco identified by genetic barcoding and the most widely used dichotomous key, and the considerable overlap in ranges of traditionally utilized metrics suggest that visual identification of coregonine larvae from Chaumont Bay is impractical. Coregonines are highly variable and plastic species, and often display wide variations in morphometric characteristics across their broad range. This study highlights the importance of developing accurate, geographically appropriate larval identification methods in order to best inform cisco restoration and management efforts.

New York↗
USGS2002

Comparison of mitochondrial DNA control region sequence and microsatellite DNA analyses in estimating population structure and gene flow rates in Atlantic sturgeon Acipenser oxyrinchus

Atlantic sturgeon Acipenser oxyrinchus is large, long-lived, and anadromous with subspecies distributed along the Atlantic (A. oxyrinchus oxyrinchus) and Gulf of Mexico (A. o. desotoi) coasts of North America. Although it is not certain if extirpation of some population units has occurred, because of anthropogenic influences abundances of all populations are low compared with historical levels. Informed management of A. oxyrinchus demands a detailed knowledge of its population structure, levels of genetic diversity, and likelihood to home to natal rivers. We compared the use of mitochondrial DNA (mtDNA) control region sequence and microsatellite nuclear DNA (nDNA) analyses in identifying the stock structure and homing fidelity of Atlantic and Gulf coast populations of A. oxyrinchus. The approaches were concordant in that they revealed moderate to high levels of genetic diversity and suggested that populations of Atlantic sturgeon are highly structured. At least six genetically distinct management units were detected using the two approaches among the rivers surveyed. Mitochondrial DNA sequences revealed a significant cline in haplotype diversity along the Atlantic coast with monomorphism observed in Canadian populations. High levels of nDNA diversity were also observed among populations along the Atlantic coast, including the two Canadian populations, probably resulting from the more rapid rate of mutational and evolutionary change at microsatellite loci. Estimates of gene flow among populations were similar between both approaches with the exception that because of mtDNA monomorphism in Canadian populations, gene flow estimates between them were unobtainable. Analyses of both genomes provided high resolution and confidence in characterizing the population structure of Atlantic sturgeon. Microsatellite analysis was particularly informative in delineating population structure in rivers that were recently glaciated and may prove diagnostic in rivers that are geographically proximal along the south Atlantic coast of the US.

Journal of Applied Ichthyology↗
USGS2019

Chronic wasting disease—Research by the U.S. Geological Survey and partners

Introduction Chronic wasting disease (CWD) is the only transmissible spongiform encephalopathy, a class of invariably fatal neurodegenerative mammalian diseases associated with a misfolded cellular prion protein found in wild free-ranging animals. Because it has a long incubation period, affected animals in Cervidae (the deer family; referred to as “cervids”) may not show signs of disease for several years. While signs are not specific to CWD, affected cervids (deer, elk, moose, and reindeer) show changes in appearance (such as progressive weight loss) and changes in behavior such as stumbling, tremors, and teeth grinding. CWD can be transmitted by direct contact or through a contaminated environment. The causative prion agent is highly resistant to degradation. In recent decades, CWD has transitioned from a novel, obscure prion disease of cervids with limited geographical distribution, to a disease that poses substantial ecological, agricultural, and economic risks across large regions of North America. Since its discovery in free-ranging elk and deer populations in the western United States in the 1980s, CWD has been reported in captive or free-ranging cervid populations in 26 States, 3 Canadian Provinces, the Republic of South Korea, Finland, Sweden, and Norway. In addition, the proportion of CWD-infected animals is increasing in many areas where the disease is already established. In some heavily affected areas, total cervid numbers have decreased over time due to CWD, which suggests that these cervid populations may not be sustainable in the long-term. The U.S. Geological Survey (USGS) conducts wildlife disease surveillance and research to support management of CWD-affected species and their habitats. The scientific information is relevant to governmental agencies that manage wildlife and their habitats including the U.S. Fish and Wildlife Service, the National Park Service, the U.S. Department of Agriculture, and other Federal, State, and Tribal agencies as well as conservation partners (non-governmental organizations, businesses, and private landowners). Each project description in this report (1–30) includes the non-USGS collaborators (Federal, State, Tribal agencies, universities) and a USGS point of contact (principal investigator). If there are USGS publications associated with the project, a publication list is provided at the end of each project description.

Alberta, California, Colorado, Idaho, Iowa, Kansas↗
USGS1995

Canvasback ducks

Canvasbacks ( Aythya valisineria ) are unique to North America and are one of our most widely recognized waterfowl species. Unlike other ducks that nest and feed in uplands, diving ducks such as canvasbacks are totally dependent on aquatic habitats throughout their life cycle. Canvasbacks nest in prairie, parkland, subarctic, and Great Basin wetlands; stage during spring and fall on prairie marshes, northern lakes, and rivers; and winter in Atlantic, Pacific, and Gulf of Mexico bays, estuaries, and some inland lakes. They feed on plant and animal foods in wetland sediments. Availability of preferred foods, especially energy-rich subterranean plant parts, is probably the most important factor influencing geographic distribution and habitat use by canvasbacks. In spite of management efforts that have included restrictive harvest regulations and frequent hunting closures in all or some of the flyways (Anderson 1989), canvasback numbers declined from 1955 to 1993 and remain below the population goal (540,000) of the North American Waterfowl Management Plan (USFWS and Canadian Wildlife Service 1994). Causes for this apparent decline are not well understood, but habitat loss and degradation, low rates of recruitment, a highly skewed sex ratio favoring males, and reduced survival of canvasbacks during their first year are considered important constraints on population growth.

Book chapter↗
USGS2005

Broad-scale predictors of canada lynx occurrence in eastern North America

The Canada lynx (Lynx canadensis) is listed as a threatened species throughout the southern extent of its geographic range in the United States. Most research on lynx has been conducted in the western United States and Canada; little is known about the ecology of lynx in eastern North America. To fill critical knowledge gaps about this species, we modeled and mapped lynx occurrence using habitat and weather data from 7 eastern states and 3 Canadian provinces. Annual snowfall, road density, bobcat (L. rufus) harvest, deciduous forest, and coniferous forest were compared at 1,150 lynx locations and 1,288 random locations. Nineteen a priori models were developed using the information-theoretic approach, and logistic regression models were ranked using Akaike's Information Criterion (AIC) and by our ability to correctly classify reserved data (Kappa). Annual snowfall and deciduous forest predicted lynx presence and absence for a reserved dataset (n = 278) with 94% accuracy. A map of the probability of lynx occurrence throughout the region revealed that 92% of the potential habitat (i.e., >50% probability of occurrence) was concentrated in a relatively contiguous complex encompassing northern Maine, New Brunswick, and the Gaspe?? peninsula of Quebec. Most of the remaining potential habitat (5%) was on northern Cape Breton Island in Nova Scotia. Potential habitat in New Hampshire, Vermont, and New York was small (1,252 km2), fragmented, and isolated (>200 km) from known lynx populations. When federally listed as threatened in the contiguous United States in 2000, inadequate regulations on federal lands were cited as the primary threat to Canada lynx. However, the majority of potential lynx habitat in the eastern United States is on private lands and continuous with potential habitat in Canada. Therefore, lynx conservation in eastern North America will need to develop partnerships across national, state, and provincial boundaries as well as with private landowners.

Journal of Wildlife Management↗
USGS2015

Who invented the mule deer ( Odocoileus hemionus )? On the authorship of the fraudulent 1812 journal of Charles Le Raye

The captivity journal of Charles Le Raye was first published in 1812 as a chapter in A topographical description of the state of Ohio, Indiana Territory, and Louisiana , a volume authored anonymously by a late officer in the U. S. Army. Le Raye was purported to be a French Canadian fur trader who, as a captive of the Sioux, had travelled across broad portions of the Missouri and Yellowstone river drainages a few years before the Lewis and Clark expedition (1804-1806), and his account of the land, its people, and its natural resources was relied upon as a primary source by generations of natural historians, geographers, and ethnographers. Based directly on descriptions of animals in the published journal, the naturalist Constantine S. Rafinesque named seven new species of North American mammals, including what are currently recognized as the mule deer ( Odocoileus hemionus ) and a Great Plains subspecies of white-tailed deer ( O. virginianus macrourus ). Unfortunately, Le Raye never existed, and historical, geographical, and ethnographical evidence indicates that the journal is fraudulent. Determining the author of this work is relevant to identifying the sources used to construct it, which may help us to understand the real animals upon which Rafinesque's species are based. Traditionally, authorship of the volume was attributed to Jervis Cutler, but his role in composing the fraudulent Le Raye journal has been called into question. In this paper, I present additional evidence supporting the hypothesis that Jervis Cutler bears primary responsibility for the Le Raye journal and that he had the background, opportunity, and potential motive to author it.

Archives of Natural History↗
USGS2019

Habitat rehabilitation in the Detroit River area of concern

Loss and degradation of fish and wildlife habitat is a long-standing issue in the Detroit River. The Detroit River Remedial Action Plan helped agencies and stakeholder groups reach agreement on impaired beneficial uses, including loss of fish and wildlife habitat, and helped mobilize all stakeholders to rehabilitate habitat. Many organizations played key roles, including the Detroit River Public Advisory Council, Detroit River Canadian Cleanup, State of the Strait Conferences, American and Canadian Heritage River Initiatives, Detroit River International Wildlife Refuge, and Western Lake Erie Watersheds Priority Natural Area. Accomplishments include: 14 habitat restoration projects on both the Canadian and U.S. side of the Detroit River; 53 soft shoreline engineering projects in the watershed; nine fish spawning reefs in the river, common tern habitat in four locations; and many wetland and green infrastructure projects. Based on Detroit River habitat restoration efforts over the last 32 years, the following advice is offered: reach agreement on severity and geographic extent of the problem; practice adaptive management; involve habitat experts up front in project design; establish quantitative targets for project success; ensure sound multidisciplinary technical support; start with demonstration projects; treat habitat projects as experiments; involve citizen scientists in monitoring; measure benefits; communicate and celebrate successes; and promote education and outreach.

Michigan, Ontario↗
USGS2019

Techniques for estimating the magnitude and frequency of peak flows on small streams in the binational U.S. and Canadian Lake of the Woods–Rainy River Basin upstream from Kenora, Ontario, Canada, based on data through water year 2013

A binational study was initiated to update statistical equations that are used to estimate the magnitude and frequency of peak flows on streams in Manitoba and Ontario, Canada, and Minnesota that are contained within the binational Lake of the Woods–Rainy River Basin upstream from Kenora, Ontario, Canada. Hydraulic engineers use peak streamflow data to inform designs of bridges, culverts, and dams, and water managers use peak streamflow data to inform regulation and planning activities. However, long-term streamflow measurements are available at few locations along the more than 20,000 miles of stream/ditch networks within the binational Lake of the Woods–Rainy River Basin upstream from Kenora, Ontario, Canada. Estimates of peak-flow magnitudes for 66.7-, 50-, 20-, 10-, 4-, 2-, 1-, and 0.2-percent annual exceedance probabilities equivalent to annual flood-frequency recurrence intervals of 1.5-, 2-, 5-, 10-, 25-, 50-, 100-, and 500-year recurrence intervals, respectively, are presented for 49 streamgages in Minnesota and adjacent areas in the Province of Ontario, Canada, based on data collected through water year 2013. Peak-flow frequency information was subsequently used in regression analyses to develop equations relating peak flows for selected recurrence intervals to various basin and climatic characteristics. The study area includes 49 streamgages located in the binational Lake of the Woods–Rainy River Basin upstream from Kenora, Ontario, Canada, and is represented by southern portions of the Canadian Provinces of Manitoba (2 percent) and Ontario (56 percent) and the northern portion of the U.S. State of Minnesota (42 percent). The study area was represented by three regions that were defined in previous studies in the U.S. State of Minnesota and another in the Canadian Province of Ontario. The two Minnesota regions A and B were developed using a multiple regression method and hydrologic landscape units were used to validate regions in Minnesota. The Ontario region A was developed using a multiple regression method and standardized residuals from the 100-year recurrence intervals. Canadian maximum instantaneous peak-flow data were converted from a calendar year to a water year (October 1 to September 30) and where the annual maximum instantaneous peak-flow value was not available in HYDAT, the Sangal method was applied to known average daily flow values to estimate an annual maximum instantaneous peak-flow value. Geographic information system software was used to calculate eight characteristics investigated as potential explanatory variables in the regression analyses. The procedure for estimating peak-flow frequency for selected exceedance probabilities for a specific ungaged site depends on whether the site is near a streamgage on the same stream or is on an ungaged stream. For an ungaged site near a streamgage on the same stream, the drainage-area ratio method can be used. For an ungaged site on an ungaged stream, the regional regression equations developed for this study should be used. All equations presented in this study will be incorporated into StreamStats, a web-based geographic information system tool developed by the U.S. Geological Survey. StreamStats allows users to obtain streamflow statistics, basin characteristics, and other information for user-selected locations on streams through an interactive map.

Manitoba, Minnesota, Ontario↗
USGS1980

Differentiation in Coregonus zenithicus in Lake Superior

Morphological variation in Coregonus zenithicus has long plagued biologists working on Lake Superior ciscoes. Some of this variation is due to allometric growth; earlier workers incorrectly recognized large C . zenithicus as a distinct species, C . nigripinnis cyanopterus . Coregonus reighardi dymondi is a variant of C . zenithicus in northern bays of Lake Superior and Lake Nipigon. The morphological differences between members of spring and fall spawning populations of C . zenithicus in Lake Superior are no greater than those between geographically separate populations. We conclude that spawning time and geographic isolation act similarly in effecting differentiation of coregonine populations, and that populations with different spawning times do not necessarily represent different species. Key words : Coregonus zenithicus , cisco, Great Lakes, multivariate morphometrics, endangered species, taxonomy

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS1974

Karyotypic analyses of twenty-one species of molossid bats (Molossidae: Chiroptera)

Examination of 135 specimens representing 21 species from seven genera of the family Molossidae revealed diploid numbers ranging from 34 to 48. Seventeen species from six genera have diploid numbers of 48. Geographic variation and polymorphism were found only in Eumops glaucinus . Chromosomal variation within the family is presumed to be primarily due to changes in diploid number resulting from Robertsonian translocations.

Canadian Journal of Genetics and Cytology↗
USGS2001

Declining scaup populations: A retrospective analysis of long-term population and harvest survey data

We examined long-term databases concerning population status of scaup (lesser [ Aythya affinis ] and greater scaup [ A. marila ] combined) and harvest statistics of lesser scaup to identify factors potentially limiting population growth. Specifically, we explored evidence for and against the general hypotheses that scaup populations have declined in association with declining recruitment and/or female survival. We examined geographic heterogeneity in scaup demographic patterns that could yield evidence about potential limiting factors. Several biases exist in survey methodology used to estimate scaup populations and harvest statistics; however, none of these biases likely accounted for our major findings that (1) the continental scaup breeding population has declined over the last 20 years, with widespread and consistent declines within surveyed areas of the Canadian western boreal forest where most lesser scaup breed; (2) sex ratios of lesser scaup in the U.S. harvest have increased (more males now relative to females); and (3) age ratios of lesser scaup in the U.S. harvest have declined (fewer immatures now relative to adults), especially in the midcontinent region. We interpreted these major findings as evidence that (1) recruitment of lesser scaup has declined over the last 20 years, particularly in the Canadian western boreal forest; and (2) survival of female lesser scaup has declined relative to that of males. We found little evidence that harvest was associated with the scaup population decline. Our findings underscore the need for both improvements and changes to population survey procedures and new research to discriminate among various hypotheses explaining the recent scaup population decline.

North America↗
USGS1994

Circum-North Pacific tectonostratigraphic terrane map

The companion tectonostratigraphic terrane and overlap assemblage of map the Circum-North Pacific presents a modern description of the major geologic and tectonic units of the region. The map illustrates both the onshore terranes and overlap volcanic assemblages of the region, and the major offshore geologic features. The map is the first collaborative compilation of the geology of the region at a scale of 1:5,000,000 by geologists of the Russian Far East, Japanese, Alaskan, Canadian, and U.S.A. Pacific Northwest. The map is designed to be a source of geologic information for all scientists interested in the region, and is designed to be used for several purposes, including regional tectonic analyses, mineral resource and metallogenic analyses (Nokleberg and others, 1993, 1994a), petroleum analyses, neotectonic analyses, and analyses of seismic hazards and volcanic hazards. This text contains an introduction, tectonic definitions, acknowledgments, descriptions of postaccretion stratified rock units, descriptions and stratigraphic columns for tectonostratigraphic terranes in onshore areas, and references for the companion map (Sheets 1 to 5). This map is the result of extensive geologic mapping and associated tectonic studies in the Russian Far East, Hokkaido Island of Japan, Alaska, the Canadian Cordillera, and the U.S.A. Pacific Northwest in the last few decades. Geologic mapping suggests that most of this region can be interpreted as a collage of fault-bounded tectonostratigraphic terranes that were accreted onto continental margins around the Circum- . orth Pacific mainly during the Mesozoic and Cenozoic (Fujita and ewberry, 1983; 1987; Parfenov, 1984, 1991; Howell, 1985; Watson and Fujita, 1985; Parfenov and Natal'in, 1984; Jones and others. 1987; Monger and Berg, 1987, Fujita and Cook. 1990; Zonenshain and others. 1990; Natal'in, 1991, 1993; Moore and others, 1992; Silberling and others, 1992; Nokleberg and others. 1992, 1993, 1994a; Parfenov and others. 1993; Plaflcer and Berg, 1994; Tabor, 1994). This map is the result of extensive geologic mapping and associated tectonic studies in the Russian Far East, Hokkaido Island of Japan, Alaska, the Canadian Cordillera, and the U.S.A. Pacific Northwest in the last few decades. Geologic mapping suggests that most of this region can be interpreted as a collage of fault-bounded tectonostratigraphic terranes that were accreted onto continental margins around the Circum- . orth Pacific mainly during the Mesozoic and Cenozoic (Fujita and ewberry, 1983; 1987; Parfenov, 1984, 1991; Howell, 1985; Watson and Fujita, 1985; Parfenov and Natal'in, 1984; Jones and others. 1987; Monger and Berg, 1987, Fujita and Cook. 1990; Zonenshain and others. 1990; Natal'in, 1991, 1993; Moore and others, 1992; Silberling and others, 1992; Nokleberg and others. 1992, 1993, 1994a; Parfenov and others. 1993; Plaflcer and Berg, 1994; Tabor, 1994). On the companion map and in the descriptions bel?w· terranes are interpreted according to inferred tectonic environments. These environments are (I) cratonai; (2) passive continental margin; (3) metamorphosed continental margin; (4) continental-margin arc; (5) island arc; (6) oceanic crust, seamount, and ophiolite; (7) accretionary wedge and subduction zone: (8) turbidite basin; and (9) metamorphic for terranes that are too highly-deformed and metamorphosed to de~ermine the original tectonic environment. For terranes with complex geologic histories, the chosen color indicates the tectonic environment most prevalent during this history of the terrane. The tectonic environments inf~rred for igneous rocks are both temporal and genetic. The temporal environments are preaccretion and postaccretion. The genetic environments are subduction-related, rift-related, and collisional (anatectic)- related. In addition to terranes, the map also depicts postaccretion units that include: (I) Cenozoic and Mesozoic overlap assemblages of sedimentary and volcanic rocks that are deposited across two or more terranes that formed generally after accretion of most terranes in the region; (2) Cenozoic and Mesozoic basinal deposits that occur within a terrane or on the craton; (3) plutonic rocks. The postaccretion igneous units are identified by age-lithologic abbreviations and by name. These overlap assemblages and basinal deposits formed mainly during sedimentation and magmatism that occurred after accretion of terranes to each other or to a continental margin. Overlap assemblages provide minimum ages on the timing of accretion of terranes. Some Cenozoic and Mesozoic overlap assemblages and basinal deposits, as well as fragments of terranes, are extensively offset by movement along postaccretion faults. In addition, in onshore areas, the map depicts major preaccretion plutonic rocks that are limited to individual terranes. and in offshore areas. the map depicts major oceanic plates,-ocean floor magnetic lineations. oceanic spreading ridges, and seamounts. The map consists of five sheets. Sheets I and 2 depict, at a scale of I :5.000.000. the tectonostratigraphic terranes. preaccretion plutonic rocks, and postaccretion Cenozoic and Mesozoic overlap sedimentary, volcanic. and plutonic assemblages, and basinal deposits for the Circum- orth Pacific including the Russian Far East, northern Hokkaido Island of Japan, Alaska. the Canadian Cordillera, part of the U.S.A. Pacific Northwest. and adjacent offshore areas. Sheet 3 provides the list of map units for Sheets I and 2. Sheet 4 is a index map showing generalized onshore terranes and overlap assemblages for onshore parts of the Circum-North Pacific at a scale of I: I 0,000,000. Sheet 4 is a guide to the more complicated onshore features depicted on Sheets I and 2. Sheet 5 is an index map showing the major geographic regions for the Circum-North Pacific. Significant differences exist between the representation of onshore and offshore geology on Sheets I and 2. These are: (I) compared to the onshore part of the map, the offshore part is depicted in a more schematic fashion because of more limited data and because the offshore terranes and early Cenozoic and older overlap assemblages generally are obscured by extensive late Cenozoic sedimentary cover that is not shown unless thicker than two kilometers; (2) marginal contacts of offshore Cenozoic and Cretaceous sedimentary basins do not match contacts of onshore Cenozoic and Cretaceous sedimentary units because offshore basins are limited to those regions with sediment thicknesses greater than two kilometers; (3) stratigraphic columns, included at the end of this explanation. are provided only for onshore terranes because the geology of offshore terranes is generally less well-known; and (4) for simplicity, the major onshore Cenozoic sedimentary basins are generally not defined and described separately because the onshore part of the map is designed to emphasize terranes and overlap volcanic assemblages that are crucial for both for tectonic and metallogenic analyses published elsewhere (Nokleberg and others, 1993, 1994a). Several key geologic sources were used in the compilation of the map. For Alaska. the basic outcrop pattern for the map is from Beikman (1980), Gehrels and Berg (1992, 1994). Barker and others ( 1994). Brew (1994), and Moli-Stalcup and others ( 1994b). The distribution of terranes is from Jones and others (1987) and Monger and Berg (1987), with modification by Grantz and other (1991 ). Worall (199 1 ), okleberg and others (1993, 1994a), the cited references, and the Alaskan co-authors of this report. For the Canadian Cordillera. the basic outcrop pattern is from Monger and Berg ( 1987), Wheeler and other (1988). and Wheeler and McFeeley ( 1991) with modifications by the Canadian authors. For the northern part of the Russian Far East. the basic outcrop pattern is from So unov (1985) with modifications by the Russian authors. For the outhern part of the Russian Far East, the basic outcrop pattern is from Krasny (1991) and Bazhanov and Oleinik ( 1986) with modification by the Russian authors. The Russian Far East part of the map is the first attempt to define and delineate terranes in that region. In their compilation. the Russian authors utilized the methodology of U.S.A. and Canadian geologists. Because this map is the first attempt to display the terranes. Cenozoic and Mesozoic overlap assemblages. basinal deposit , and plutonic belts of the Russian Far East. the Russian author will appreciate constructive sugge tions for improving the map.

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